This invention relates to dispensers for fluids, typically for soaps, lotions and detergents, and in particular, to a new and improved fluid dispenser valve which requires lower operating forces than conventional dispenser valves. Dispensers of this nature are sometimes referred to as valves and sometimes as pumps, and "dispenser valve" or "valve" will be used herein as meaning a valve or a pump.
The conventional soap and lotion dispenser utilizes O-rings for seals, and a typical device is Bobrick Model B-111, produced by Bobrick Washroom Equipment, Inc. In this type of device, a piston is mounted in a valve body of a fluid storage container, with the piston sliding in the valve body and having O-rings for sealing purposes. The piston is pushed inward to force fluid out from the valve chamber, typically manually, mechanically or electrically, and is pushed outward by a spring to return the piston to the rest position and to suck fluid into the valve body. While this type of design has been satisfactory for many purposes, a relatively high force is required for operation, typically requiring a manual push in the order of six to eight pounds. While satisfactory for many installations, a dispenser with a lower operating force is desired for environments where the valve will be utilized by handicapped individuals.
Accordingly, it is an object of the present invention to provide a new and improved fluid dispenser valve which will have the desirable operating characteristics of conventional valves, while being operable with substantially less force, typically in the range of three to four pounds maximum. It is a further object of the invention to provide such a new and improved valve which will operate with a source of supply having a substantial negative pressure head or a substantial positive pressure head and at the same time not be subject to dripping or leaking of fluid.
These and other objects, advantages, features and results will more fully appear in the course of the following description.